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Study of Near-Sonic Flows

近音速流动的研究

基本信息

批准号：
14205137
负责人：
NAKAHASHI Kazuhiro
金额：
$ 34.78万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-14205137/
关键词：
Sonic Shock Wave Computational Fluid Dynamics Optimization CFD 遷音速空気抵抗最適設定

项目摘要

Numerical and experimental studies of flows at near-sonic speed have been conducted. The following are the major results obtained by this research.1. The TAS-code, an in-house unstructured-grid based CFD soft, was sophisticated and a practical engineering tool for analyzing and designing transonic airplanes was constructed.2. An efficient direct optimization code using the adjoint equation was developed. It was applied to optimize the wing-nacelle-pylon integration of a transonic airplane and an important engineering information was obtained.3. An efficient, multi-disciplinary optimization code for designing a high-performance transonic airplane was developed using the genetic algorithm and the data mining method.4. A new method to improve the prediction accuracy of the drag by CFD was developed. With this method, an optimization of winglet, which is generally very sensitive to the solution accuracy, becomes possible.5. A sonic plane at Mach 0.98 was aerodynamically optimized using the TAS-code. The result showed 25% improvement of the lift-to-drag ratio and the important knowledge of a general condition for an efficient sonic plane was obtained.6. Dynamically unstable tendency of a reentry capsule at transonic speed was numerically analyzed and a prediction method for the dynamic stability of the capsule was proposed.7. Physics of base flows of a high-speed vehicle was numerically investigated with the LES/RANS hybrid methodology. It was shown that the time-series characteristics at transonic speed was significantly different from other speed regimes.8. An elevon reversal phenomena at near-sonic speed of a reusable space plane was numerically investigated using the TAS-code and the cause was identified. The method to prevent the elevon reversal was proposed.9. Various flow phenomena of weak shock waves were experimentally and numerically investigated for the physical understanding.

已经对近音速流动进行了数值和实验研究。本研究取得的主要成果如下： 1． TAS代码是一种内部基于非结构化网格的CFD软件，非常复杂，构建了用于分析和设计跨音速飞机的实用工程工具。2．开发了使用伴随方程的高效直接优化代码。将其应用于某型跨音速飞机机翼-短舱-外挂架一体化优化，获得了重要的工程信息。 3．利用遗传算法和数据挖掘方法，开发了一种高效、多学科的高性能跨音速飞机设计优化代码。 4．开发了一种提高CFD阻力预测精度的新方法。通过该方法，可以对通常对求解精度非常敏感的小翼进行优化。 5．使用 TAS 代码对 0.98 马赫的音速飞机进行了空气动力学优化。结果表明升阻比提高了25%，获得了高效音速飞机一般条件的重要知识。 6．对再入舱在跨音速下的动态不稳定趋势进行了数值分析，提出了返回舱动态稳定性的预测方法。 7．使用 LES/RANS 混合方法对高速车辆基本流动的物理现象进行了数值研究。结果表明，跨音速速度下的时间序列特征与其他速度状态有显着差异。 8．使用 TAS 代码对可重复使用太空飞机近音速下的升降舵反转现象进行了数值研究，并查明了原因。提出了防止升降舵反转的方法。 9．为了物理理解，对弱冲击波的各种流动现象进行了实验和数值研究。